Method of estimating the position of a user device using radio beacons and radio beacons adapted to facilitate the methods of the invention

Abstract

Disclosed is the estimation of the position of a user device (18) using radio beacons (B1-B4) which are operable at a plurality of transmit power levels. The radio beacons (B1-B4) may transmit their position and current transmit power level. Estimates of distance between a user device and a radio beacon can take into account both received signal strength and the current transmit power level of the radio beacon. The position of the user device (18) can be estimated taking into account whether a radio beacon (B1-B4)) can be detected at a given transmit power level. The transmit power level of the radio beacon may vary according to a cycle. The transmit power level of the radio beacon may be changed to facilitate positioning, for example in response to a signal from a user device. A radio beacon (B1-B4) changes transmit power level in a cycle. The radio beacon can reduce transmit power level responsive to a signal. The radio beacon (B1-B4) may be compatible with Bluetooth short range wireless connectivity standard core specification version 4.0.

Description

FIELD OF THE INVENTION[0001]The invention concerns a method of estimating the position of a user device using radio beacons which have a plurality of discrete transmit power levels, and radio beacons adapted to facilitate estimates of the position of a user device.BACKGROUND TO THE INVENTION[0002]In recent years there has been considerable interest in determining the position of user devices, such as cellular telephones, portable electronic computers and other portable personal user devices. Systems based on the use of global satellite navigation systems (e.g. GPS) are useful out of doors but are of limited use within buildings and have only limited positioning accuracy. Accordingly, it is desirable to determine the position of user devices using alternative technologies, particularly those which are useful indoors, either as an alternative to or in combination with global satellite navigation systems to obtain more accurate measurements of position.[0003]It is known to determine po...

AI Technical Summary

Benefits of technology

The patent describes a method for estimating the position of a user device by changing the transmit power level of a radio beacon. The user device or a positioning controller sends a signal to the beacon to reduce its power level, which causes the beacon to decrease its signal strength. This reduction in signal strength is measured by the user device or positioning controller and used to calculate the user device's distance from the beacon. The method also takes into account environmental factors that may affect the signal's strength, such as temperature or the type of positioning algorithm used. The technical effect of this patent is to provide a more accurate and reliable method for estimating the position of a user device by using a radio beacon.

Problems solved by technology

Systems based on the use of global satellite navigation systems (e.g. GPS) are useful out of doors but are of limited use within buildings and have only limited positioning accuracy.

Images